Pebble Smart's PS111 Smart Doggie Doorbell, or pet chime, is a helpful dog training tool to teach your dog how to enter and leave your home more like a human. This dog doorbell helps alleviate common frustrations from damages associated with your dog scratching and damaging your wood or glass doors when he or she wants to leave or enter your home. The doorbell includes a built-in treat holder behind the large push plate to make doorbell ringing training fun and easy. When your dog smells the treat through the hole in the middle, he or she will naturally try to lick and nudge to the push plate to reach the treat and trigger the doorbell. Overtime, your dog will be able to ring the doorbell without using a treat as an incentive. You can also install a second doggie doorbell inside so your dog can ring it whichever way he or she is going. The doggie doorbell features 36 melodies to select from so you will never be tired of a particularly tune.